Beneficial effects of starting oral cysteamine treatment in the first 2 months of life on glomerular and tubular kidney function in infantile nephropathic cystinosis.

Nephropathic cystinosis is a rare lysosomal storage disease whose basic defect, impaired transport of cystine out of lysosomes, results in intracellular cystine storage. Affected individuals exhibit renal Fanconi Syndrome in infancy, end-stage kidney disease at approximately 10 years of age, and many other systemic complications. Oral cysteamine therapy mitigates the detrimental effects on glomerular function and prevents most of the late complications of the disease but has not shown benefit with respect to the early tubular damage of cystinosis. This is because cystinosis is generally diagnosed in the second year of life, after the damage to kidney tubular function has already occurred. We longitudinally evaluated 6 infants diagnosed and treated with cysteamine from before 2 months of age. The 4 infants with good compliance with cysteamine and consistently low leucocyte cystine levels maintained normal eGFR values, exhibited only minor degrees of renal Fanconi Syndrome, and maintained normal serum levels of potassium, bicarbonate, phosphate, and calcium without electrolyte or mineral supplementation through 2, 4, 10 and 16 years of age. Thus, renal Fanconi syndrome can be attenuated by early administration of cysteamine and renew the call for molecular-based newborn screening for cystinosis.

Topical Stabilized Cysteamine as a New Treatment for Hyperpigmentation Disorders: Melasma, Post-Inflammatory Hyperpigmentation, and Lentigines.

Cysteamine is an aminothiol naturally present in cells of the human body as an antioxidant resulting from the degradation of Coenzyme A. Physiologically it is well distributed in mammalian tissues. Highly concentrated in human milk, cysteamine acts as an intrinsic antioxidant and is known for its protective role. Multiple studies now document that cysteamine is a potent skin depigmenting agent. Historically, its rapid oxidation and very offensive odor made it difficult for topical use until recently when stabilization of cysteamine was achieved. This has led to an acceptable galenical form for topical application. Since 2015, the efficacy, safety, and tolerability of stabilized cysteamine (st.Cys) has been demonstrated in multiple clinical studies, as well a case reports. Stabilized cysteamine has demonstrated significant effectiveness for the treatment of melasma by two double-blind randomized and vehicle control trials. Stabilized cysteamine (st.Cys) has shown to be as effective as well-known depigmenting therapies, including triple combination cream or tranexamic acid mesotherapy, with higher tolerability. A recent clinical trial has shown considerable efficacy of topical cysteamine for the treatment of senile lentigines, which are usually considered to be resistant to topical depigmenting agents. Topical stabilized cysteamine can be regarded to as one of the most potent treatments available for hyperpigmentation disorders in humans. J Drugs Dermatol. 2021;20(12): 1276-1279. doi:10.36849/JDD.6367.

Bone Disease in Nephropathic Cystinosis: Beyond Renal Osteodystrophy.

Patients with chronic kidney disease (CKD) display significant mineral and bone disorders (CKD-MBD) that induce significant cardiovascular, growth and bone comorbidities. Nephropathic cystinosis is an inherited metabolic disorder caused by the lysosomal accumulation of cystine due to mutations in the CTNS gene encoding cystinosin, and leads to end-stage renal disease within the second decade. The cornerstone of management relies on cysteamine therapy to decrease lysosomal cystine accumulation in target organs. However, despite cysteamine therapy, patients display severe bone symptoms, and the concept of "cystinosis metabolic bone disease" is currently emerging. Even though its exact pathophysiology remains unclear, at least five distinct but complementary entities can explain bone impairment in addition to CKD-MBD: long-term consequences of renal Fanconi syndrome, malnutrition and copper deficiency, hormonal disturbances, myopathy, and intrinsic/iatrogenic bone defects. Direct effects of both CTNS mutation and cysteamine on osteoblasts and osteoclasts are described. Thus, the main objective of this manuscript is not only to provide a clinical update on bone disease in cystinosis, but also to summarize the current experimental evidence demonstrating a functional impairment of bone cells in this disease and to discuss new working hypotheses that deserve future research in the field.

Use of Human Induced Pluripotent Stem Cells and Kidney Organoids To Develop a Cysteamine/mTOR Inhibition Combination Therapy for Cystinosis.

BACKGROUND: Mutations in CTNS-a gene encoding the cystine transporter cystinosin-cause the rare, autosomal, recessive, lysosomal-storage disease cystinosis. Research has also implicated cystinosin in modulating the mTORC1 pathway, which serves as a core regulator of cellular metabolism, proliferation, survival, and autophagy. In its severest form, cystinosis is characterized by cystine accumulation, renal proximal tubule dysfunction, and kidney failure. Because treatment with the cystine-depleting drug cysteamine only slows disease progression, there is an urgent need for better treatments. METHODS: To address a lack of good human-based cell culture models for studying cystinosis, we generated the first human induced pluripotent stem cell (iPSC) and kidney organoid models of the disorder. We used a variety of techniques to examine hallmarks of cystinosis-including cystine accumulation, lysosome size, the autophagy pathway, and apoptosis-and performed RNA sequencing on isogenic lines to identify differentially expressed genes in the cystinosis models compared with controls. RESULTS: Compared with controls, these cystinosis models exhibit elevated cystine levels, increased apoptosis, and defective basal autophagy. Cysteamine treatment ameliorates this phenotype, except for abnormalities in apoptosis and basal autophagy. We found that treatment with everolimus, an inhibitor of the mTOR pathway, reduces the number of large lysosomes, decreases apoptosis, and activates autophagy, but it does not rescue the defect in cystine loading. However, dual treatment of cystinotic iPSCs or kidney organoids with cysteamine and everolimus corrects all of the observed phenotypic abnormalities. CONCLUSIONS: These observations suggest that combination therapy with a cystine-depleting drug such as cysteamine and an mTOR pathway inhibitor such as everolimus has potential to improve treatment of cystinosis.

The effect of food and liquid pH on the integrity of enteric-coated beads from cysteamine bitartrate delayed-release capsules.

BACKGROUND: Cysteamine bitartrate delayed-release (DR) capsule (Procysbi®) is approved for treatment of nephropathic cystinosis in the USA, Canada, and the EU. The capsules contain cysteamine bitartrate beads that are enteric coated with acid-resistant Eudragit L 30 D-55, preventing drug release in the acidic stomach environment while allowing dissolution of the beads in the more alkaline environment of the small intestine. Patients who have difficulty swallowing capsules can open capsules, sprinkle beads onto 4 ounces of a suitable food or liquid, gently mix, and consume the entire content within 30 minutes. Foods found to be suitable for administration, and described in the Procysbi US labeling, include fruit juices (except grapefruit juice), applesauce, and berry jelly; there are minor variations in the foods and liquids recommended by regulatory authorities in other countries. This study aimed to assess the stability of enteric-coated beads exposed to additional foods at different conditions to expand the list of suitable foods for drug administration. METHODS: For each test condition, beads from eight opened 75 mg cysteamine bitartrate DR capsules were gently mixed with test food and maintained at a prespecified temperature and duration; remaining undissolved beads were then recovered from the food. The recovered beads were split into two portions: one assayed for remaining drug content and the other subjected to dissolution testing to assess the effect on the drug-release profile. RESULTS: The results show that bead integrity was maintained when mixed with foods at pH values <5.5 at all time points when refrigerated (2°C-8°C) and at room (20°C-22°C) and lukewarm (37°C-41°C) temperatures. Bead integrity was not maintained when mixed with foods at pH values of ≥5.5 at room temperature. CONCLUSION: The results from this in vitro dissolution study help in identifying additional foods that may be used for the administration of cysteamine bitartrate DR beads from opened capsules using the sprinkle method.

Efficacy of N,N'bis-(2-mercaptoethyl) isophthalamide on mercury intoxication: a randomized controlled trial.

BACKGROUND: Chronic mercury intoxication is a severe health issue and occurs especially in gold mining communities. Common chelators used for improving mercury elimination are not everywhere available and challenged by poor cell wall penetration. This study is part of a feasibility trial and the aim was to gather first information about the efficacy of the newly developed chelator N,N'bis-(2-mercaptoethyl) isophthalamide (NBMI) on chronic mercury intoxication. METHODS: In this three-armed, placebo-controlled randomized trial, 36 miners with mercury urine levels exceeding 15 µg/l were administered 100 mg NBMI, 300 mg NBMI or placebo for 14 days. Levels of mercury in urine [µg/l and µg/g creatinine] and plasma l were analyzed. Therapeutic effect was assessed using the medical intoxication score (MIS) and its single health outcomes (e.g. excessive salivation, sleeping problems), fatigue scores, a neuromotoric test battery (CATSYS) and a neurological outcome (Finger to nose test). RESULTS: Physical fatigue was significantly decreased in the 300 mg NBMI group compared to the control. Mercury concentration in urine following 300 mg NBMI treatment was significantly lowered compared to control, however, this effect was less distinct with adjustment for creatinine. CONCLUSION: NBMI showed an effect on physical fatigue and there were indications to positive effects on other symptoms as well. More comprehensive studies are mandatory to verify the effects of NBMI as a novel tool for treating mercury intoxications. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02486289 . Date of registration: June 24, 2015.

MRI Brain Volume Measurements in Infantile Neuronal Ceroid Lipofuscinosis.

BACKGROUND AND PURPOSE: Infantile neuronal ceroid lipofuscinosis is a devastating neurodegenerative storage disease caused by palmitoyl-protein thioesterase 1 deficiency, which impairs degradation of palmitoylated proteins (constituents of ceroid) by lysosomal hydrolases. Consequent lysosomal ceroid accumulation leads to neuronal injury, resulting in rapid neurodegeneration and childhood death. As part of a project studying the treatment benefits of a combination of cysteamine bitartrate and N-acetyl cysteine, we made serial measurements of patients' brain volumes with MR imaging. MATERIALS AND METHODS: Ten patients with infantile neuronal ceroid lipofuscinosis participating in a treatment/follow-up study underwent brain MR imaging that included high-resolution T1-weighted images. After manual placement of a mask delineating the surface of the brain, a maximum-likelihood classifier was applied to determine total brain volume, further subdivided as cerebrum, cerebellum, brain stem, and thalamus. Patients' brain volumes were compared with those of a healthy population. RESULTS: Major subdivisions of the brain followed similar trajectories with different timing. The cerebrum demonstrated early, rapid volume loss and may never have been normal postnatally. The thalamus dropped out of the normal range around 6 months of age; the cerebellum, around 2 years of age; and the brain stem, around 3 years of age. CONCLUSIONS: Rapid cerebral volume loss was expected on the basis of previous qualitative reports. Because our study did not include a nontreatment arm and because progression of brain volumes in infantile neuronal ceroid lipofuscinosis has not been previously quantified, we could not determine whether our intervention had a beneficial effect on brain volumes. However, the level of quantitative detail in this study allows it to serve as a reference for evaluation of future therapeutic interventions.

Development of 4-hexadecyl-4,7-diaza-1,10-decanedithiol (HDD) kit for the preparation of the liver cancer therapeutic agent Re-188-HDD/lipiodol.

INTRODUCTION: A lipiodol solution of (188)Re-4-hexadecyl-2,2,9,9-tetramethyl-4,7-diaza-1,10-decanedithiol (HTDD) has been successfully developed for liver cancer therapy; however, its preparation requires a multi-step synthesis and it is characterized by a low labeling yield. METHODS: We synthesized a new compound, 4-hexadecyl-4,7-diaza-1,10-decanedithioacetate (AHDD), without gem dimethyl groups to address these issues. AHDD was formulated into a kit and was labeled with (188)Re. Biodistribution study was performed using normal BALB/c mice. RESULTS: The kit was labeled with (188)Re with a high efficiency (98.8±0.2%). After extraction with lipiodol, the overall yield of (188)Re-HDD/lipiodol was as high as 90.2±2.6%. A comparative biodistribution study of (188)Re-HTDD and (188)Re-HDD was performed in normal mice after intravenous injection. The lungs were identified as the main uptake site due to capillary-blockage. (188)Re-HDD/lipiodol showed a significantly higher lung uptake than that of (188)Re-HTDD/lipiodol (p<0.05). CONCLUSION: The newly synthesized (188)Re-HDD/lipiodol showed improved radiolabeling yield and biodistribution results compared to (188)Re-HTDD/lipiodol, and may therefore be more suitable for liver cancer therapy.

Cysteamine (Lynovex®), a novel mucoactive antimicrobial & antibiofilm agent for the treatment of cystic fibrosis.

BACKGROUND: There remains a critical need for more effective, safe, long-term treatments for cystic fibrosis (CF). Any successful therapeutic strategy designed to combat the respiratory pathology of this condition must address the altered lung physiology and recurrent, complex, polymicrobial infections and biofilms that affect the CF pulmonary tract. Cysteamine is a potential solution to these unmet medical needs and is described here for the first time as (Lynovex®) a single therapy with the potential to deliver mucoactive, antibiofilm and antibacterial properties; both in oral and inhaled delivery modes. Cysteamine is already established in clinical practice for an unrelated orphan condition, cystinosis, and is therefore being repurposed (in oral form) for cystic fibrosis from a platform of over twenty years of safety data and clinical experience. METHODS: The antibacterial and antibiofilm attributes of cysteamine were determined against type strain and clinical isolates of CF relevant pathogens using CLSI standard and adapted microbiological methods and a BioFlux microfluidic system. Assays were performed in standard nutrient media conditions, minimal media, to mimic the low metabolic activity of microbes/persister cells in the CF respiratory tract and in artificial sputum medium. In vivo antibacterial activity was determined in acute murine lung infection/cysteamine nebulisation models. The mucolytic potential of cysteamine was assessed against DNA and mucin in vitro by semi-quantitative macro-rheology. In all cases, the 'gold standard' therapeutic agents were employed as control/comparator compounds against which the efficacy of cysteamine was compared. RESULTS: Cysteamine demonstrated at least comparable mucolytic activity to currently available mucoactive agents. Cysteamine was rapidly bactericidal against both metabolically active and persister cells of Pseudomonas aeruginosa and also emerging CF pathogens; its activity was not sensitive to high ionic concentrations characteristic of the CF lung. Cysteamine prevented the formation of, and disrupted established P. aeruginosa biofilms. Cysteamine was synergistic with conventional CF antibiotics; reversing antibiotic resistance/insensitivity in CF bacterial pathogens. CONCLUSIONS: The novel mucolytic-antimicrobial activity of cysteamine (Lynovex®) provides potential for a much needed new therapeutic strategy in cystic fibrosis. The data we present here provides a platform for cysteamine's continued investigation as a novel treatment for this poorly served orphan disease.

Copper deficiency in patients with cystinosis with cysteamine toxicity.

OBJECTIVES: To assess whether copper deficiency plays a role in the recently described cysteamine toxicity in patients with cystinosis, and to examine whether polymorphisms in copper transporters, lysyl oxidase, and/or type I procollagen genes could be responsible for the occurrence of cysteamine toxicity in a small subset of patients with cystinosis. STUDY DESIGN: Thirty-six patients with cystinosis were included: 22 with Fanconi syndrome (including 7 with cysteamine toxicity), 12 after renal transplantation, 1 receiving hemodialysis, and 1 with ocular cystinosis. Serum copper and ceruloplasmin levels and urinary copper/creatinine ratio were measured. Genes ATP7A and CTR1 (encoding copper transporters), LOX (encoding lysyl oxidase), and COL1A1 and COL1A2 (encoding type I procollagen) were analyzed in patients with (n = 6) and without (n = 5) toxicity. Fibroblast (pro)collagen synthesis was compared in patients with (n = 3) and those without (n = 2) cysteamine toxicity. RESULTS: All 22 patients with Fanconi syndrome had increased urinary copper excretion. Serum copper and ceruloplasmin levels were decreased in 9 patients, including all 7 patients with cysteamine toxicity. No specific sequence variations were associated with toxicity. All fibroblasts exhibited normal (pro)collagen synthesis. CONCLUSION: Patients with cystinosis with cysteamine toxicity demonstrate copper deficiency. This can cause decreased activity of lysyl oxidase, the enzyme that generates the aldehydes required for collagen cross-linking. Thus, copper supplementation might prevent cysteamine toxicity.

Heptahelical protein PQLC2 is a lysosomal cationic amino acid exporter underlying the action of cysteamine in cystinosis therapy.

Cystinosin, the lysosomal cystine exporter defective in cystinosis, is the founding member of a family of heptahelical membrane proteins related to bacteriorhodopsin and characterized by a duplicated motif termed the PQ loop. PQ-loop proteins are more frequent in eukaryotes than in prokaryotes; except for cystinosin, their molecular function remains elusive. In this study, we report that three yeast PQ-loop proteins of unknown function, Ypq1, Ypq2, and Ypq3, localize to the vacuolar membrane and are involved in homeostasis of cationic amino acids (CAAs). We also show that PQLC2, a mammalian PQ-loop protein closely related to yeast Ypq proteins, localizes to lysosomes and catalyzes a robust, electrogenic transport that is selective for CAAs and strongly activated at low extracytosolic pH. Heterologous expression of PQLC2 at the yeast vacuole rescues the resistance phenotype of an ypq2 mutant to canavanine, a toxic analog of arginine efficiently transported by PQLC2. Finally, PQLC2 transports a lysine-like mixed disulfide that serves as a chemical intermediate in cysteamine therapy of cystinosis, and PQLC2 gene silencing trapped this intermediate in cystinotic cells. We conclude that PQLC2 and Ypq1-3 proteins are lysosomal/vacuolar exporters of CAAs and suggest that small-molecule transport is a conserved feature of the PQ-loop protein family, in agreement with its distant similarity to SWEET sugar transporters and to the mitochondrial pyruvate carrier. The elucidation of PQLC2 function may help improve cysteamine therapy. It may also clarify the origin of CAA abnormalities in Batten disease.

Transduced PEP-1-FK506BP ameliorates atopic dermatitis in NC/Nga mice.

Immunophilin, FK506-binding protein 12 (FK506BP), is a receptor protein for the immunosuppressive drug FK506 by the FK506BP/FK506 complex. However, the precise function of FK506BP in inflammatory diseases remains unclear. Therefore, we examined the protective effects of FK506BP on atopic dermatitis (AD) in tumor necrosis factor-α (TNF-α)/interferon-γ (IFN-γ)-induced HaCaT cells and 2,4-dinitrofluorobenzene-induced AD-like dermatitis in Nishiki-nezumi Cinnamon/Nagoya (NC/Nga) mice using a cell-permeable PEP-1-FK506BP. Transduced PEP-1-FK506BP significantly inhibited the expression of cytokines, as well as the activation of NF-κB and mitogen-activated protein kinase (MAPK) in TNF-α/IFN-γ-induced HaCaT cells. Furthermore, topical application of PEP-1-FK506BP to NC/Nga mice markedly inhibited AD-like dermatitis as determined by a histological examination and assessment of serum IgE levels, as well as cytokines and chemokines. These results indicate that PEP-1-FK506BP inhibits NF-κB and MAPK activation in cells and AD-like skin lesions by reducing the expression levels of cytokines and chemokines, thus suggesting that PEP-1-FK506BP may be a potential therapeutic agent for AD.

4-S-Cysteaminylphenol-loaded magnetite cationic liposomes for combination therapy of hyperthermia with chemotherapy against malignant melanoma.

Tyrosine analogs are good candidates for developing melanoma chemotherapies because melanogenesis is inherently toxic and expressed uniquely in melanocytic cells. The sulfur homolog of tyrosine, 4-S-cysteaminylphenol (4-S-CAP), was shown to be a substrate of melanoma tyrosinase and can cause selective cytotoxicity of melanocytes and melanoma cells. Previously, in order to improve the adsorption of magnetite nanoparticles to target cell surfaces, and generate heat in an alternating magnetic field (AMF) for cancer hyperthermia, we produced hyperthermia using magnetite cationic liposomes (MCL) that have a positive charge at the liposomal surface. In the present study, we constructed 4-S-CAP-loaded MCL (4-S-CAP/MCL), which act as a novel modality, combining melanoma-specific chemotherapy by 4-S-CAP with intracellular hyperthermia mediated by MCL. The 4-S-CAP/MCL exerted 4-S-CAP-mediated anticancer effects on B16 melanoma cells in vitro and in vivo. Moreover, after intratumoral injection of 4-S-CAP/MCL in vivo, the melanoma nodules were heated to 45 degrees C under an AMF. Significantly higher therapeutic effects were observed in mice treated with the combination therapy mediated by 4-S-CAP/MCL plus AMF irradiation compared with mice treated with 4-S-CAP/MCL alone (without AMF) or mice treated with hyperthermia alone (MCL + AMF irradiation). These results suggest that this novel therapeutic tool is applicable to the treatment of malignant melanoma.

Antioxidants suppress mortality in the female NZB x NZW F1 mouse model of systemic lupus erythematosus (SLE).

Inflammation produces reactive oxygen intermediates (ROI) that cause vascular damage and activate T lymphocytes. Conversely, antioxidants not only protect tissue from oxidative damage but also suppress immune reactivity. The objective of this study was to examine immunomodulatory effects of the non-enzymatic antioxidants, N-acetylcysteine (NAC) and cysteamine (CYST), on autoimmune disease, glomerulonephritis, and mortality in the female B/W mouse model of human systemic lupus erythematosus (SLE). The development of murine lupus was assessed during the lifespan of female B/W mice given NAC or CYST. Morbidity and mortality were assessed daily. At 6 week intervals mice were examined for weight change, albuminuria, serum BUN, antibodies to DNA, and IgG immunoglobulin levels. Serum prolactin, estrogen and progesterone were measured at 18 weeks of age. In a parallel study, NAC- and CYST-treated and control B/W mice were examined at 24 weeks of age for interval renal histopathology, lymphocyte adhesion molecule expression, and antibody titers and in vitro cytokine production in response to immunization with DNP-KLH. CYST significantly suppressed development of albuminuria and azotemia at 36 and 42 weeks of age compared to control and NAC-treated mice. NAC significantly suppressed anti-DNA antibody levels at 24 weeks. In contrast CYST significantly increased anti-DNA antibody levels at 18 weeks of age (P < 0.001 CYST vs control and NAC-treated mice). Kidneys of CYST-treated mice also had accelerated inflammatory histologic changes despite their lower incidence of albuminuria and azotemia. Mean (+/- s.e.m.) survival of control mice was 33 +/- 2 weeks compared to 38 +/- 2 weeks in NAC-treated mice (P < 0.05 vs control), and 48 +/- 2 weeks in the CYST-treated group (P < 0.01 vs control mice). The antioxidants, NAC and CYST, significantly improved mortality in the female B/W mouse model of SLE. NAC suppressed autoantibody formation and modestly prolonged survival. CYST, despite its augmentation of anti-DNA levels and renal inflammatory changes, inhibited the development of renal insufficiency and markedly improved survival. These findings suggest that ROIs play a role in the pathogenesis of lupus nephritis and that antioxidants reduce the damage causing renal insufficiency. Antioxidants may be a beneficial adjunctive therapy in the treatment of human SLE.

[The influence of diamide on the realization of the radioprotective effect of beta-mercaptoethylamine in the postradiation period]. / Vliianie diamida na realizatsiiu radiozashchitnogo éffekta beta-merkaptoétilamina v postradiatsionnom periode.

In the experiments with Ehrlich ascites tumor cells it was shown that specific oxidation of cellular glutathione after irradiation produced no effect on the degree of radiation injury in the air, but resulted in a decrease of radioprotective effect of beta-mercaptoethylamine. From these results it follows that for a complete realization of radioprotective effect normal level of cellular glutathione is necessary.

Cysteamine protects against diarrhoea induced by castor oil. This protective effect can be potentiated by SH-alkylator treatment.

Cysteamine given orally or subcutaneously protects against diarrhoea induced by castor oil. Pretreatment with N-EM, an SH-alkylator, does not influence the occurrence of diarrhoea. Furthermore, N-EM pretreatment does not influence the protective effect of loperamide or difenoxilate. However, N-EM pretreatment potentiates the protective effects of cysteamine or indomethacin against diarrhoea. These findings indicate that sulfhydryl-sensitive processes may also be involved in the mechanisms of diarrhoea.